divide_to_string panics on negative dividend

[csarn]

Using version 0.8.0, this testcase panics:

    #[test]
    fn divide() {
        fraction::division::divide_to_string(-1, 1, 10, false);
    }

Panic:

thread 'tests::divide' panicked at 'internal error: entered unreachable code', C:.cargo\registry\src\github.com-1ecc6299db9ec823\fraction-0.8.0\src\division.rs:350:21

[dnsl48]

hi @csarn,
Thank you for reporting the issue!
I think we missed that bit in the documentation, but these functions do not work with negative numbers.
We may need to document this limitation better.

[csarn]

Thanks for documenting this! I also worked around this issue by using fraction for the absolute values and adding a minus sign to the resulting string when applicable.